Method and means for forming hollow articles



March 4, 1930. HOLMES 1,749,428

METHOD AND MEANS FOR FORMING HOLLOW ARTICLES Filed May 27, 1926 2Sheets-Sheet 1 Fly 2 K yVEZTOR B M r W ATTORNEYS O March 4, 1930. K, OLE 1,749,428

.METHOD AND MEANS FOR FORMING HOLLOW ARTICLES Filed May 27, 1926 2Sheets-Sheet 2 4 Fly. 5

INVENT R BY M 1 111% ATTORNEYS Patented Mar. 4, 1930 UNITED, STATESPATENT, OFFICE EARL K. HOLMES, OF CLEVELAND, OHIO,

ASSIGNOR, BY MESNE ASSIGNMENTS, TO

STEEL AND-TUBES, IN C., OF CLEVELAND, OHIO, A CORPORATION OF OHIO METHODAND" MEANS FOR FORMING HOLLOW ARTICLES This invention relates to the artof forming hollow metal articles and more particularly to means andmethods for changing the configuration of hollow or tubular metalpieces.

An object of this invention is to provide a method by which hollow ortubular metal articles may be readily and easily given a desiredcross-sectional configuration.

Another object is to provide means for changing the cross sectionalconfiguration of hollow articles without causing undesired changes suchas collapsing or buckling of the articles.

Another object is to provide a simple apparatus for changing theconfiguration of hollow articles which may be readily applied tostandard machines.

Other objects will hereinafter appear.

The invention will be better understood from the description of onepractical embodiment of the apparatus comprising a part thereof,illustrated in the accompanying drawings, in which,

Fig. 1 is a front elevationof a vertical press, provided with dies fordeforming a metal tube.

Fig. 2 is a side elevation of the press shown in Fig. 1.

Fig. 3 is a fragmentary cross section of the apparatus shown in Figs. 1and 2 taken on the line 33 and shown on an enlarged scale.

Fig. 4 is a view similar to Fig. 3, but showing the parts in a differentpositlon, and,

Fig. 5 is another View similar to Flg. 3 and showing the parts in stillanother position.

The machine illustrated comprises a standard 1 carrying a cross-head 2which is reciprocated vertically by links 3 and cranks- 4. Below thecross-head, the frame is provided with a stationary abutment 5. Dies 6and 7 are carried by the cross-head and abutment, respectively, and arebrought together by the reciprocation of the cross-head to .formarticles into the shape desired.

Application filed May 27, 1926. Serial No. 111,990.

reciprocates between plates 10 attached to the abutment. Shoulders onthe blocks and plates engage each other at 11 to limit upward movement,of the blocks. A plurality of rods 12 are fixed to the block and extendthrough the abutment and through a channel 13 carried by rods 14threaded at their upper ends into the abutment. Around the rods 12 arehelical compression springs 15 which press at their lower ends upon thechannel and at their upper ends upon shoulders on the rods, and thusnormally maintain the block at its uppermost position, where theshoulders 11 are in engagement. Extending through the die 7 and block 9are ejector plungers 16 urged upwardly by comparatively weak helicalsprings 17 positioned within the block. The plungers are prevented fromrotation by being keyed to the die to maintain the concave upper ends ofthe plunger in proper relation to the die surface.

the EJ801701 plungers to limit their downward movement, so that theupper surface of the plungers in their lowermost position will formcontinuations of the die surface.

The operation of the device is as follows With the dies separated, asshown in Figs. 1, 2 and 3, the operator places a tube 20 on the concaveends of the plungers 16. He then engages the power for bringing thecross-head 2 down toward the abutment. As soon as die 6 engages theupper surface of tube 20, the plungers 16 are pressed downwardly,compressing the springs 17, until the plugs 19 abut the fixed plugs 21at the bottom of the cylindrical spring recesses. The ejector plungertops are now aligned with the surface of die 7 and through the remainderof the forming operation may be considered as a part of die 7.

As the cross-head continues downwardly, parts of its force goes intocompressing springs'lfi and part into deforming tube 20, the partsassuming substantially the position shown in Fig. 4, wherein the tube isslightly flattened, but die 7 and block 9 have been moved downwardly,compressing springs 15. By permitting this downward movement against thesprings, the deforming force is applied to the tube much more slowly andsmoothly than would be the case if the lower die were fixed and thispermits the metal in the tube to flow or readjust it self, so that thetube flattens gradually instead of buckling at the points of contactwith the die, as would be the case if the deforming force were moresuddenly applied.

When block 9 reaches its lowermost position, shown in Fig. 5, in whichit rests upon the abutment 5, the dies will be nearly in contact and thetube substantially in the form shown in Fig. 5. The cross-head willcontinue further sufiiciently to press the dies tightly together,completing the forming of the tube. Upon upward movement of thecross-head, springs 15 return the die 7 and block 9 to their originalposition. After shoulders 11 are in engagement with the block 9, furtherupward motion on the part of die 6 permits the ejector plungers to moveupwardly and return the tube to its original position, permitting it tobe easily removed and another inserted.

The above process is both simple and rapidly performed, the apparatuslikewise being simple and efficient, and is applicable to hard orbrittle materials which cannot be readily formed by common formingoperations for instance, tubes of high carbon steel, which wouldcollapse or buckle under ordinary forming operations may be readilyshaped by the apparatus'and process above set forth. While I havedescribed the apparatus embodying one form of my invention and themethod connected therewith in some detail, it will be obvious that manymodifications and variations may be made in both the ap-' paratus andmethod above set forth, without departing from the scope of theinvention and I therefore do not limit myself to. the preciseembodiments shown, but claim as my invention all such variations andmodifications coming within the scope of the appended claims.

- What is claimed is:

1."Apparatus for changing the cross sectional configuration of a hardsteel tube which comprises a suitably recessed die, means for advancingthe said die, an oppositely disposed die toward which the first said diemay be advanced and being suitably recessed, the second said die beingcomposed of a plurality of parts, certain of the parts projecting aboveothers of the parts, means for yieldingly sup porting the saidprojecting parts, means for yieldingly supporting the remaining parts ofthe said die,'and means for fixedly supporting all of the parts of thedie at one end of the stroke.

2. The method of shaping a length of brittle tnetal tubing whichcomprises placing the tubing between spaced dies, causing relative-mo'vement of the dies to compress the tubing therebetween, and causingone of the dies to yieldably with progressively increasing force resistthe movement of the opposing die until the cross-sectional configurationof the length of tubing is changed.

3. The method of shaping a length of brittle metal tubing whichcomprises placing the tubingbetween spaced movable dies, advancing oneof said dies toward the opposing die to compress the articletherebetween, and causing the last mentioned die to resist yieldably andwith progressively increasing force the advancing die until thecross-sectional shape of the tubing is changed.

4. The method of transversely shaping a tubular metal article whichcomprises placing the article between spaced recessed die members,forcing the die members together under yieldable progressivelyincreasing pressure to partially bend the article transversely, andapplying unyielding pressure to completely shape the article.

5. The method of transversely shaping a hollow metal article whichcomprises placing the article bet-ween spaced movable dies, advancingone of said dies toward the opposed die and against the article wherebyopposite exterior sides of the article are forced toward each othercausing the last mentioned die to resist yieldably and with increasingpressure the advancing die until the article is partially shaped, andfinally causing the last mentioned die to rigidly resist the advancewhereby the article is completely shaped.

6. The method of transversely shaping a hollow metal article whichcomprises placing the article between spaced recessed die members whichare adapted to cooperate to form a cavity of the desire shape, forcingthe die members together u der yieldable progressively increasingpressure to bend the tube, and finally forcing the die members togetherunder unyielding pressure until the article assumes the shape of thecavity.

7. A device for shaping a hollow metal article which comprisesoppositely recessed die members, means for positively advancing one diemember toward the opposing die member to compress a hollow metalarticle, means causing the opposing die member to yieldably incresinglyresist the pressure of the advancing die member, and means for finallycausing the opposing die member to rigidly resist the advancing diemember.

8. A device for shaping a hollow metal ar-' ticle which comprisesoppositely recessed die members, means for advancing one die membertowards the opposed die member, compresses the article and finallycontacts with the opposing die member.

9. "A device for shaping a hollow metal article which comprises upgerand lower oppositely recessed die mem ers adapted to receive thearticle, means for advancing one die member toward the opposing diemember whereby the article is compressed therebetween, means forgradually increasing the rem sistance of the one die member to theadvance of the opposing die member, and a plunger for lifting thearticle .from the recess of the opposing die member upon separation ofthe of the die members.

In testimony whereof I hereunto afiix my signature this 4th day of May,1926. p

EARL K, HOLMES.

